Problem: you are in an ambivalent cooperative situation. Your partner shows collaboration but also exploits you, in a maybe complex situation or history.

Solution: Don't think too much about the past, the future counts. Look at the immediate past and act accordingly. This is a simplification of the decision situation primarily. It allows you to act on a sound principle, if you want to.

Comments: If you change you mode of cooperation, communicate why you do this. The strategy won't work, if it is not understood by your partners, and they are used to exploit you.